The singer and her partner, Tammy, are the new parents of a son and a daughter
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Melissa Etheridge and her partner Tammy are the new parents of a son and a daughter, PEOPLE has learned.

Their son Miller Steven and their daughter Johnnie Rose were born on Tuesday. Both Tammy and babies are in excellent health, according to their rep.

“The creation of life brings about immeasurable love, and pours hope into the future,” the couple said in a statement. “The joy will help carry us through our upcoming sleepless nights.”

Etheridge, 45, and Tammy, 31, who has acted on TV’s Committed and The L Word, exchanged vows in Malibu in September 2003. Etheridge already has two children from a previous relationship with Julie Cypher: daughter Bailey Jean, 9, and son Beckett, 7.

Bailey Jean and Beckett were conceived via artificial insemination courtesy of friend and rock legend David Crosby

In October 2005, Etheridge told PEOPLE that having more kids was in the works. “I look forward to bringing more children into a loving home and having them there my entire life,” she said. “It could heal a lot of things that have happened to me.”

Etheridge, diagnosed with breast cancer in 2004, made her post-chemo stage debut at last year’s Grammys, where she stopped the show with her rendition of Janis Joplin’s “Piece of My Heart.”

Crediting Michaels as being instrumental in her successful health battle, Etheridge also told PEOPLE in 2005: “We thought about children before the diagnosis but were sidetracked.”

When the couple announced this pregnancy in April, the singer and the actress said in a joint statement on Etheridge’s official Web site, “To answer the obvious question: We used an anonymous donor from a bank.”

They also said, “These are our first two babies conceived together, but not our first time mothering together. For the past five years, we have been parenting two children from a previous time in Melissa’s life. The twins will be a joyful addition to our loving home.”

Saying, “We are a blessed family,” the two requested “that no gifts be sent. Any gifts we receive we will donate to a local women’s shelter. However, well wishes are more than welcome!”